An internal combustion engine may include an engine block defining a plurality of cylinder bores, a crankshaft rotatably supported in the engine block, and pistons connected to the crankshaft and configured to reciprocate within the cylinder bores. Typically, each piston may include a skirt pivotally connected to the crankshaft, and a crown connected to a distal end of the skirt. A combustion bowl may be formed on an end face of the crown to receive injected fuel, and annular grooves may be formed in an outer surface of the crown to receive associated rings. A cooling passage may be annularly formed inside the crown, between the bowl and the cooling passage, to circulate engine oil that may cool the bowl.
During operation of the engine, fuel and air is combusted inside the cylinder bore (and inside the bowl), to generate heat and pressure that is turned into mechanical work. Over a period of time, a piston pin bore of the piston (that may receive a piston pin) may wear out, thereby causing a change in a size of the piston pin bore. For example, the size of the piston pin bore may increase (e.g., a diameter and/or a circumference of the piston pin bore may increase). In this regard, an amount of space (e.g., a gap) between the piston pin bore (prior to any wear) and the piston pin is to be maintained to ensure proper operation of the piston. Accordingly, as the piston pin bore experiences wear, an excessive motion between the piston and the rod is created, which excessive motion may lead to seizure of the piston pin and scuffing of the piston.
U.S. Patent Application Publication No. 20150345421 (hereinafter the '421 publication) is directed to a piston of an internal combustion engine. The piston may include a piston crown with annular grooves, a combustion chamber bowl, and a piston skirt with a pin bore to receive a pin. However, the '421 publication does not disclose monitoring wear of a piston pin bore.